The present invention relates to MPW (Multi-Project Wafer) shuttle service and particularly to a system and method for MPW shuttle service with a mechanism to exchange devices between MPW shuttles.
Development of IC (Integrated Circuit) fabrication technology in the semiconductor industry has led to exponential growth in mask costs for each process. Taiwan Semiconductor Manufacturing Company (TSMC) has announced a foundry industry device prototyping service called Cyber shuttle or MPW shuttle service enabling designers to explore the benefits of leading-edge technology without committing to large volume wafer starts, and helping clients to shorten their new design development and reduce the development costs including the mask cost during trial production and characteristic evaluation on real chip trial stage. In addition, the MPW shuttle service dramatically reduces NRE (Non-Recurring Engineering) charges for small wafer volumes, enabling fast, low-cost prototyping.
The MPW shuttle service enables different clients to book an MPW shuttle and deliver their product design to the MPW shuttle service provider. Once all of the design information is received, each design will be translated and produced on a common mask with appropriate allocation. Subsequent to IC fabrication, the MPW shuttle service provider delivers the ICs to the corresponding clients.
FIG. 1 illustrates a schematic diagram of the MPW shuttle service. In FIG. 1, a mask 110 including product designs A (111), B (112) and C (113) is commonly produced for different clients. The mask 110 is transferred to each die 101 of the wafer 100 by photolithography. Subsequent to IC fabrication, the MPW shuttle service provider delivers IC products A (120), B (130) and C (140) to the corresponding clients. The MPW shuttle service enables clients to share costs by producing a common mask for rapid processing of new products and designs to silicon-proven and verification status.
The MPW shuttle service provider may provide a booking mechanism for clients to book specific MPW shuttles. A complete schedule of the MPW shuttle includes the three periods of MPW reservation and mask data preparation, mask production, and wafer start. The MPW shuttle is open for reservation until a cut off date, by which time clients must provide mask data for their booked product designs. Subsequent to the cut off date, the common mask is produced, and wafer fabrication begins.
FIG. 2 shows an example of an MPW shuttle MPWS1. The schedule of MPW shuttle MPWS1 includes the three periods P11, P12, and P13. In period P11, there are five device designs, D1˜D5, booked on MPW shuttle MPWS1. However, mask data for device D3 has missed the cut off date T1 of MPW shuttle MPWS1. This presents two disadvantages. First, since MPW shuttle MPWS1 has reserved a position for device D3 and which shares the common mask, mask production period P12 is delayed to time T2 to await mask data for device D3. The subsequent wafer start period P13 is also delayed. Second, the device D3 could be pushed out of MPW shuttle MPWS1, and rescheduled on another MPW shuttle. If the successive MPW shuttle has no capacity for the device D3, the design cycle and prototyping will be seriously delayed.
FIG. 3 shows an example of two successive MPW shuttles MPWS1 and MPWS2. The MPW shuttles MPWS1 and MPWS2 are booked for devices D1˜D5 and D6˜D10 respectively. Similarly, the mask data of device D3 has missed cut off date T1 for MPW shuttle MPWS1. Mask data for device D8, however, has met the cut off date T1 for MPW shuttle MPWS1. In practice, there is no existing solution to exchange devices between MPW shuttles. Therefore, MPW shuttle MPWS1 is delayed, and device D8 is still scheduled to be processed with MPW shuttle MPWS2 although its mask data has already been provided. In addition, the conventional MPW shuttle service does not provide a pull-in function, in which a pull-in demand for a specific device design means a specific device design requires priority fabrication. Conventionally, all devices are processed equally regardless of priority status.